Chair base



FIG. 1 is a perspective view of a chair base according to the presentinvention.

FIG. 2 is a side view of the chair base of the present invention, withthe opposite side being a mirror image thereof.

FIG. 3 is a front view of the chair base of the present invention.

FIG. 4 is a rear view of the chair base of the present invention.

FIG. 5 is a top view of the chair base of the present invention; and,

FIG. 6 is a bottom view of the chair base of the present invention.

The broken lines shown in the Figures are for environmental purposesonly, and form no part of the claimed design.

CLAIM The ornamental design for a chair base, as shown and described.